Clamp



M mh25,'1941. 'Fl L MCKENNA 2,236,439-` cLAgP Filed April 4, 1940 2 Sheets-Sheet 2 Patented Mar. 25, 1941 UNIT-ED STATES rATEN cnam Frank L: Moxom, Detroit, moli Application April 4 1940', sommo. 327,928

s claims. (ci. 141-290) the arm in clamped relation. The fact that the by the toggle relationof'the elementsrenders this clamp objectionable. o

4In my present invention I provide a cam surface on the workengaging arm and a roller on the operating arm, engageable with the cam surface. The cam surface may be an Archimedes curve or of other suitable formation. one which permits a variation inthe height of the arm while maintained in locked position. A slotted link interconnects both of the arms, the link f work engaging arm is held in a single position being pivoted by a pin 'to the operating arm,v

with the slot thereof projecting over the pin in the work engaging arm. The slot permits independent movement of the arms while pro viding means whereby the working .arm may be a moved completely out of engagement with the workpiece.

Accordingly, the main objects of my invention are; to provide a clamp for a workpiece with an arm which has a range of clamping positions;

to provide a work engaging arm with a cam surface and an operating arm with a roller so `related. as to provide a variation in clamping height while maintained in locked4 relation; to

Aprovide'a'clamp with a workengaging arm having a cam surfacegand an operating arm having an engaging roller interconnected by a slotted link; to provide a clamp with a web to which bifurcated work engaging and operating arms are pivoted and-so interconnected by a link that a roller on the operating arm is engageable with acanr surface on the iwork'engaging arm; and

' in general,to provide a clamp which is simple in construction, positive in operation, and economical of manufacture.

Other objects and features of novelty of my invention will lbe either specifically pointed out or will become apparent when referring; for a. better understanding of 'my invention, to .the

following description taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a view in side elevation of a 'clam embodying features of nLv invention:

Fig. 2 is an end view of the structure illustrated 5 inFlg.1; ,`i'

Fig. 3 is an enlarged -broken sectional view of the structure illustrated in Fig. 1, taken onl the line 8-2 thereof; p 1

Fig. 4.15 an enlarged broken sectionalview of 10 4the structure illustrated'in Fig. 1, taken on-th lmet-,4 thereof; and;

Fig. 5 is afview of structure,` similar to'that -illustrated in Fig. 2. showing a modified form of 15.

my inventiom.

Fig.'6 is a vi'ew in elevation of structure similar to that illustrated -in Fig. 1, showing a further. modined form of my invention; Fig.'7 is an end view of the structure illustrated l inFiS. 6: .f2.0

Fig. 8 is an enlarged broken sectional view of the structure illustrated in Fig. 6, taken on the line l-l thereof; I

Fig. 9 is an enlargedgibroken sectional -view r' of the structure shown'in Fig. 8, takenon `the line 2 9 thereof; and,

Fig. 10 is an sectional. view of the structure illustrated in Fig. 6. taken on the'llne The clampwhich embodies my, present inve'n- 30 tion is of the type having a base which is attached adjacent to a work support with the work engaging ann in position to engage and hold the workpiece against its support.l In the figure, I have illustrated a work supporting base I0 having a workpiece, Il placed in position to be engaged by thelarm of the clamp I2. The clamp I2 comprises' a standard ifl having a base Il and an upwardly Vextife'nrlingcentral web I5. A work engaging ormio pivoted to. tno-'web is 9 Von a pivot I1. The arrn`=-i2is preferably ycono 'structed of a pair off'stampings Il-which are" offset to provide' a1bifurcted`f end portion il when the outer end portions` ;a'r'e 'welded together as illustrated in'lig. 3. j y Anoperatingarmli isiixewisemmrapauof stampings 22 which are offset-to. provide a'bifurcated end portion fromthejoined 1 portion u forming ine handle :of f srne ons or 50 the operating arm 2| are pivot'ed totl'ieweb Il on the pivot 2l. A'link- 2l, inadeffrom a'pai'r'of stampinga is-disposed between the elements 22v of. the bifurcated Portion'of the operating arm 4and between thestiunpings-v Il oi the bifurcated. 55 f T'I oi-*FICE f portion I3 of the work engaging arm Il. The.

link is pivoted to the operating arm on the pivot 21 and is secured to the lwork engaging arm by the pin disposed in a slot 23 of thelink. When v movement by a pin 3 I.

The work engaging arm Il is provided with cam surfaces 32 engageable by rollers 33 which are mounted on the pin 21 between the link 23 and the bifurcated portion of the operating arm 2i. 'Ihe shape of the cam surface may vary, but

I have found that a cam surface having the shape of an Archimedes curve provides locking relation between the rollers 33 and the work engains arm. The relationship between the cam surface and rollers should be such that a positive lock is provided while the work engaging arm is moved to engage and clamp the workpiece. As mentioned hereinabove, the use of a toggle link for locking the work engaging arm in position limits 'the clamp to one locking position. 'Ihe feature of moving the workengaging arm by the link pivoted to the operating arm is the same in my present clamp as in the toggle actuated clamp. 'I'he additional feature of providing the work engaging arm with various clamping positions is incorporated in my clamp.

While I have illustrated vand describedV a clamp having the arms mounted on a standard having i a single web I5 extending from the basesupport, I have shown in Fig. 5, theapplication of my principle to/a clamp employing a pair of spaced webs 35 projecting from supporting flanges 33. In this construction, the operating arm 31 is formed of two stampings which are welded together throughout their length and disposed between the webs 35 and pivoted on a pin 3l. The pair of links 39 are disposed outside of the arm 31 and are attached to the operating arm 2| bya pin 42.- A roller 4I; is disposed between the links and is also mounted on the pin 42. 'I'he opposite ends of the links 39 are slotted and pivoted to the work engaging arm 31 as illustrated in Fig. 1. The roller engages the cam surfaces 32 on the arm 31v Vand functions in a manner as set forth hereinabove for clamping theworkpieces to the base l0. l

In Fig. 6, I have illustrated a further form of my invention.. that wherein the handle 24 is changed to form an extension of .the links 25 of the structure illustrated in Fig. 1. That is to say,

-a handle I5 is pivoted on the pivot 23 of the arm I6 while a pair of links 46 are pivoted on the pinl 25 to the frame casting I3. The`pln 21 carries the rollers 33 and extends through a slot 41 in the handle 45. The advantage of this construction resides in the toggle lock provided by the links 46 and the pivot of the handle as the rollers are advanced along the curved surface 32.'

threaded end 49, which extends through a collar 5I formed by a strap having extending legs 52 and 53 disposed in off-center relation to the col-v lar. When welded or otherwise secured to the end of the arm I6, the stud will be on thelongitudinalcenterlineofthearm. Apairofnutsll retain the stud Il in adjustable position on the end of the arm. Preferably, the element constitutingthecollarandextendinglessisfurnished separate with the clamp so that after the clamp and workpiece is located, the collar may be weldedtotheendofthearminrequired position.

ItwillthusbeseenthatIhaveprovideda clamp having a work engaging arm which is movable into and out of engagement with the workpiece by means of a link.. and which engages and clamps the work through the action of a roller on a cam surface provided on the arm. The arm may be bifurcated and secured to a support having a single web or a unit arm may be provided disposed between a pair of projecting webs employing a single roller in contact with the cam surface thereof. In either construction, the main novelty of the invention resides in the variation in the positions of the work engaging arm which is maintained locked in all of the said D0- sitions.

While I have described and illustrated several embodiments of my invention, it will be apparent to those skilled in the art that various changes, omissions, additions and substitutions may be made therein without departing-from the spirit and scope of my invention, as set forth in the accompanying claims. What I claim is:

1. A clamp including. in lcombination, a standard. a work engaging arm pivoted thereon and provided ,with a cam surface, an operating arm lpivoted on said standard, a link pivoted on said operating arm and having a slot and pin connection with said work engaging arm, and a roller on said operating arm engageable with said cam` surface, and means on said operating arm engaging said cam surface for clamping said arm.

3. A clamp including, in combination, a standard having a base and an up'standing web, a work engaging arm having bifurcated. end portions plvoted to said web, an operating arm having bifurcated end portions pivot/edito said web, a link pivoted to the bifurcated portion of said operating .arm, said link having a slot therein, a pin proiecting through said slot and supported on said bifurcated portion of Ithe work engaging arm, cam surfaces on the bifurcated portion of said work engaging arm, and rollers on said operating arm engageable with said surfaces when the workI engaging arm is in clamped position.

4. A clamp comprising a pair of angle elements disposed in spaced relation, one branch forming secure feet, the other-branch providing upstandingwebs. a work engaging arm disposed between said 'webs'and pivoted thereto, an operating arm having a bifurcated portion receiving said `webs work engaging arm and ,disposed between the bifurcated portion of said operating arm and pivoted thereto, said links being provided with a slot, a pin projecting into .the slots and throughsaid work engaging arms, said work engaging arms having a cam surface, and a roller disposed beand pivoted thereto, a pair of links spanning said tween said links on the pivot thereoi' engaeable with said camy surface when a workpiece is clamped.

5. A clamp including, incombnation, a .standard, a work engaging arm pivoted thereon' providv ed WithI a cam surface, an operating arm pivoted on said work engaging arm, a link pivoted on said standard and having a slot and pin-com nection with said operating arm, and rollers on 10 said last pin engageable with said cam. surface.

6. A clamp including, incombination, a standard, a work engaging arm pivoted thereon and provided with a cam surface, an operatlng'arm pivoted-on `.said work engaging arm and provided with a slot,A a link pivoted on said standard, a

lpin on said link extending through the slot in said operating arm, a roller pivoted on said last pin disposed in position to engage said cam surface and to belocked in adjusted position by said FRANK L. MCKENNA.- l0 

